Process for sizing paper

ABSTRACT

The new vinyl polymer dispersions are obtainable by free radical polymerisation of olefinically unsaturated monomers in the presence of a cationic polyamidoamine which has been rendered hydrophobic, and can be used as sizing agents for paper which are distinguished, in particular, by their shear, electrolyte, heat and storage stability.

The present invention relates to new vinyl polymer dispersions which arebased on olefinically unsaturated monomers and polycations which havebeen rendered hydrophobic, a process for the preparation of thesedispersions and their use as sizing agents for paper.

The preparation of cationic sizing agents for paper which are in theform of colloidally disperse solutions, in which acrylonitrile ormethacrylonitrile is polymerised with acrylic acid esters or methacrylicacid esters in the presence of specific polymeric cationic emulsifiersin an aqueous system, is known from EP 0 058 313. The specificemulsifiers are quaternisation products of terpolymers ofN,N-dimethylaminoethyl (meth)acrylate, styrene and acrylonitrile.

The preparation of colloidally disperse sizing agents for paper, whichare particularly effective for low-grade paper, in which either mixturesof (meth)acrylonitrile, styrene and acrylic acid ester or methacrylicacid ester or mixtures of styrene and acrylic acid ester or methacrylicacid ester are polymerised in the presence of the abovementionedquaternised terpolymers, is described in DE-A-3 401 573.

One disadvantage of these colloidally disperse sizing agents is theiroften unsatisfactory stability in practice in the presence ofelectrolytes and at elevated temperatures, for example above 600° C.,when high shearing forces are used, and their tendency to foam.Relatively large amounts of electrolytes occur in the papermakingprocess, for example if enzymatically degraded starch is added as anadditive to the sizing liquor. In particular, after degradation of thestarch, the enzyme activity is stopped by addition of acids, such assulphuric or hydrochloric acid; the electrolytes are then formed byaddition of bases during neutralisation of the excess acid. Sinceenzymatic degradation of starch is often also carried out at relativelyhigh temperatures of about 80°-1000° C. and the starch solution isusually added to the sizing liquor immediately, an increase in thetemperature of the sizing liquor to a maximum of these temperatures isin general to be expected. Under these conditions, the colloidallydisperse sizing agents described above coagulate partly or evencompletely. Deposits are formed on the paper machine, and the sizingeffect is reduced drastically. High shearing forces, which may alsooccur during papermaking, can lead to similar effects.

Cationic sizing agents for paper which have an improved stability and areduced tendency to foam and are built up from the same monomers as inEP 0 058 313 and DE-A-3 401 573, but where the quaternisation of theemulsifier used which is based on N,N-dimethylaminoethyl (meth)acrylate,styrene and acrylonitrile is carried out not with epichlorohydrin butwith simple monoepoxides, that is to say those which do not containhalogen, are described in DE-A-3 537 824. In this procedure, as in theexamples mentioned above, the specific cationic emulsifiers are preparedin organic solvents, which have to be replaced before or after use ofthe cationic emulsifiers in the subsequent polymerisation. Thisprocedure has disadvantages from the economic and ecological aspect.

Too great a tendency to foam, which can also lead to disturbances in thepaper-processing process, is a further disadvantage of all the sizingagents described above.

The sizing agents known from the prior art usually are not equallysuitable for beater and surface sizing of paper, or are not sufficientlyinexpensive for use in the beater sizing.

Dimeric alkyl-ketenes are known reactive sizing agents for paper. Forthe necessary distribution of the alkyl-ketene dimer in aqueoussolution, the use of cationic dispersing agents, such aspolyamidopolyamine/epichlorohydrin resins (U.S. Pat. No. 3,046,186) or"one-pot reaction products" of various carboxylic acids withpolyalkylene-polyamines and epichlorohydrin is described (EP 054 075).However, the resulting mixtures have only a limited storage stability.U.S. Pat. No. 4,087,395 describes epichlorohydrin resins ofpolyamidopolyamines, which are reacted with carboxylic acid derivativeshaving an unsubstituted acyl radical. These compounds have shown a clearsizing action on paper only in mixtures of low storage stability withketene dimers.

It has now been found that shear-, electrolyte-, heat- andstorage-stable sizing agents for beater and surface sizing of paper areobtained in an economically and ecologically advantageous process ifcertain olefinically unsaturated monomers are polymerised in thepresence of cationic polyamidoamines which have been renderedhydrophobic.

The present invention relates to a process for the preparation of vinylpolymer dispersions by emulsion polymerisation, initiated by freeradicals, of olefinically unsaturated monomers in an aqueous medium,characterised in that the emulsifier employed is a cationicpolyamidoamine which as been rendered hydrophobic, has a content ofcationic groups of between 0.01 and 0.3 charge equivalent per 100 g ofthis substance, a content of hydrophobic groups of between 0.5 and 50%by weight and a content of basic nitrogen atoms of between 0 and 3% byweight, in each case based on the cationic polyamidoamine which has beenrendered hydrophobic, and is obtainable by rendering a basicpolyamidoamine (A) hydrophobic with monocarboxylic acids (B), subsequentprotonation with acids (C) and/or quaternisation with monoepoxides (D).

In the sense of this invention, a polyamidoamine "which has beenrendered hydrophobic" is to be understood as a polyamidoamine whichcontains terminal long-chain aliphatic hydrocarbon radicals which haveat least 7 C atoms and are derived from the corresponding monocarboxylicacids.

Suitable basic polyamidoamines (A) for the preparation of the cationicpolyamidoamines which have been rendered hydrophobic are condensationproducts comprising structural units which are derived from

a1): polyamines which contain at least two amino groups which arecapable of amide formation and at least one other secondary or tertiaryamino group

and if appropriate

a2): polyamines which contain two amino groups which are capable ofamide formation,

b): saturated or unsaturated aliphatic and/or aromatic dicarboxylicacids and/or functional derivatives thereof

and if appropriate

c): omega-aminocarboxylic acids and/or lactams,

preferably 0.8 to 1.2 mol of component al), if appropriate up to 0.8 molof component a2), and if appropriate up to 1.5 mol of component c) beingemployed per mol of component b), with the proviso that the molar ratioof a):b) assumes values of between 0.8:1 and 1.2:1.

The polyamines al) preferably correspond to the formula ##STR1## whereinR₁, R₂ and R₃ independently of one another are H, methyl, ethyl or2-hydroxyethyl,

a and b independently of one another represent 0, 1, 2, 3 or 4 and

c and d independently of one another represent 1, 2, 3, 4, 5 or 6,

and/or the formula ##STR2## wherein x represents 2 or 3 and

A represents hydrogen, aminoethyl or aminopropyl.

Examples of polyamines al) of the formula (I) are diethylenetriamine,triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine,hexaethyleneheptamine, dipropylenetriamine, dihexamethylenetriamine,N-methyl-bis(3-aminopropyl)amine and tris(2-aminoethyl)amine.

Examples of polyamines al) of the formula (II) areN-(2-aminoethyl)piperazine, N,N'-bisaminoethylpiperazine andN,N'-bisaminopropylpiperazine.

Preferred polyamines a1) are triethylenetetramine, diethylenetriamineand N-methyl-bis(3-aminopropyl)amine.

The polyamines a2) preferably correspond to the formula ##STR3## whereinR₁, R₂, a and c have the abovementioned meaning, and/or the formula##STR4## and/or the formula ##STR5##

Examples of polyamines a2) are ethylenediamine, diaminopropane,1,6-diaminohexane, N-(2-hydroxyethyl)ethylenedismine,N,N'-dimethylethylenediamine, N-methyl-1,3-diaminopropane,isophoronediamine and 4,41-diaminodicyclohexylmethane.

Preferred lactams c) are, for example, ε-caprolactam and lauryl-lactam,and preferred aminocarboxylic acids c) are 6-aminocaproic acid and11-aminoundecanoic acid.

Dicarboxylic acids b) or alkyl esters thereof which are preferablyemployed are those which correspond to the formula

    R.sub.4 --O--CO--(CH.sub.2).--CO--O--R.sub.5               (VI)

wherein

R₄ and R₅ independently of one another represent hydrogen, C₁ -C₆ -alkylor phenyl, and e represents 0 or an integer from 1 to 10.

Mixtures of dicarboxylic acids b) or functional derivatives thereof canof course also be employed in the preparation of the polyamidoamines(A). The following dicarboxylic acids and dicarboxylic acid derivativesb) may be mentioned as examples:

oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid,sebacic acid, dimethyl oxalate, diethyl oxalate, diethyl malonate,succinic anhydride, glutaric acid monomethyl ester, diethyl glutarate,adipic acid monomethyl ester, dimethyl adipate, dimethyl sebacate,isophthalic acid, terephthalic acid, dimethyl isophthalate, maleicanhydride, itaconic acid, dimethyl itaconate and phthalic acid. Adipicacid is preferred.

Possible basic polyamidoamines (A) are also those in which up to 20 mol% of the secondary basic amino groups present are converted intotertiary amino groups by alkylation. Alkylation here is to be understoodas meaning reaction of the secondary amino groups with alkyl halides,alkyl alkanesulphonates and acrylic compounds. The following alkylhalides may be mentioned as examples:

methyl chloride, ethyl chloride, chloropropanol, chloroethanol andchloropropanediol.

The following alkyl alkanesulphonates may be mentioned as examples:

methyl methanesulphonate, ethyl methanesulphonate and chloropropylethanesulphonate.

The polyamidoamines are prepared in the customary manner, for example bya procedure in which components a1), if appropriate a2) and b), and ifappropriate c) are first heated to temperatures of between 100 and 150°C., and, after a maximum of 3 hours, the resulting mobile melt isfurther heated slowly to a maximum of 220° C. under normal pressure, thewater of reaction formed being distilled off. To avoid discolourations,it is advantageous to carry out the condensation with exclusion ofoxygen, and if appropriate to add carboxylic acid hydrazides in smallamounts. The mixture is distilled until the theoretical amount of waterhas been withdrawn from the equilibrium, that is to say 1 mol of watermust be split off per mol of carboxyl group of the dicarboxylic acid.

Long-chain monocarboxylic acids (B) are preferably employed forrendering the basic polyamidoamines (A) hydrophobic.

Suitable monocarboxylic acids (B) are preferably, aliphaticmonocarboxylic acids or aliphatic monohydroxycarboxylic acids having upto 32 carbon atoms.

The preferred monocarboxylic acids (B) correspond to the formulae

    R.sub.6 --COOH                                             (VII)

wherein

R₆ represents straight-chain or branched, saturated or olefinicallyunsaturated alkyl having 7 to 31 C atoms,

and

    R.sub.7 --COOH                                             (VIII)

wherein

R₇ represents straight-chain or branched, saturated or olefinicallyunsaturated monohydroxyalkyl having 7 to 31 C atoms.

Particularly preferred monocarboxylic acids (B) are furthermorehydroxycarboxylic acid polycondensates of the formula

    H--[--O--R.sub.6 --CO--].sub.f --OH                        (IX)

wherein

R₆ has the meaning given above under formula (VII) and

f represents an integer from 2 to 50, preferably from 3 to 20.

The monocarboxylic acids (B) mentioned of the formulae (VII), (VIII) and(IX) can be employed individually, but also as any desired mixture withone another.

The hydroxycarboxylic acid polycondensates (IX) are particularlypreferably reacted in the form of their functional derivatives of theformulae

    R.sub.6 --CO--[--O--R.sub.6 --CO--].sub.f --OH             (X)

    H--[O--R.sub.6 --CO--].sub.f --Cl                          (XI)

and

    R.sub.6 --CO--]--O--R.sub.6 --CO--].sub.f --Cl             (XII)

wherein

R₆ and f in each case have the abovementioned meaning,

with the basic polyamidoamines.

The derivatisation of the polycondensates (IX) is carried out, forexample, by acylation of the free alcohol function to give an ester (X)and/or activation of the free acid function to give an acid chloride(XI) or (XII).

The polycondensates (IX) are formed in a known manner (compare, forexample, Houben-Weyl, Methoden der Organischen Chemie (Methods ofOrganic Chemistry), volume XIV/2, G. Thieme Verlag) by heating thehydroxycarboxylic acids (VIII) if appropriate with addition of acids ortetraalkyl titanates, and, for example, azeotropic removal of the waterformed.

The functional derivatives of the formula (X) can be obtained from thepolycondensates (IX) by acylation of the free alcohol function with amonocarboxylic acid (VII) or acid chlorides or anhydrides thereof.

The compounds of the formulae (XI) and (XII) can be obtained by reactionof the polycondensates (IX) or of the acylated derivatives of theformula (X) with inorganic acid chlorides, such as, for example,phosphorus trichloride, phosphorus pentachloride or thionyl chloride.

The functional derivatives of the formula (X) can be employed as themonocarboxylic acids (B) individually or in any desired mixtures withone another, with the hydroxycarboxylic acid polycondensates (IX) orwith the carboxylic acids (VII) and (VIII).

The acid chlorides of the formulae (XI) and (XII) can be employedindividually or as a mixture, but advantageously not as a mixture withthe other monocarboxylic acids mentioned under (B).

Suitable hydroxycarboxylic acids (VIII) are, for example,2-hydroxydodecanoic, 2-hydroxytetradecanoic and 2-hydroxyhexadecanoicacid. Particularly preferred acids are, for example,12-hydroxyoctadecanoic acid and 11-hydroxyhexadecanoic and-pentadecanoic acid.

Corresponding unsaturated hydroxycarboxylic acids, such as12-hydroxy-9-octadecenoic acid, are also suitable compounds.

The suitable long-chain carboxylic acids (VII) include, for example,decanoic, dodecanoic, tetradecanoic, hexadecanoic, octadecanoic,eicosanoic and docosanoic acid, and the unsaturated acids oleic acid,linoleic acid, linolenic acid and docosenoic acid.

In particular, mixtures of various hydroxycarboxylic acids and mixturesof various long-chain carboxylic acids can also be employed.

To render the basic polyamidoalmines (A) hydrophobic, these areinitially introduced into the reaction vessel in molten form attemperatures of between 120 and 250° C., and the long-chain carboxylicacid (VII), the hydroxycarboxylic acid (VIII), the hydroxycarboxylicacid polycondensate (IX) or acylated or activated derivatives thereof(X), (XI) or (XII), or the mixtures mentioned of these compounds, areadded. The mixture is stirred at an unchanged temperature for between 2and 10 hours, until the reaction has ended, volatile reaction productsbeing removed.

Subsequent protonation and/or quaternisation of the basicpolyamidoamines which have been rendered hydrophobic leads to cationicpolyamidoamines which have been rendered hydrophobic. Acids (C) whichare suitable for the protonation are, for example, inorganic acids, suchas hydrochloric acid, sulphuric acid, nitric acid or phosphoric acid.Preferred acids (C) are dilute or concentrated organic carboxylic acidshaving a short alkyl chain which contains 1 to 4 C atoms, such as formicacid, acetic acid, propionic acid or lactic acid. Acetic acid isparticularly preferred. The amount of acid (C) is in general chosen sothat all the amino functions of the basic polyamidoamine which has beenrendered hydrophobic are protonated completely. However, it is alsopossible to employ less than or more than the stoichiometric amount ofacid (C).

If acid chlorides of the formulae (XI) or (XII) are used for renderingthe polyamidoamines (A) hydrophobic, partial protonation already occursduring the reaction due to the hydrogen chloride liberated, which islargely trapped by free amine functions of the polyamidoamine.

Monoepoxides (D) which are suitable for the quaternisation are ethyleneoxide, 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide,1,2-epoxydecane, 1,2-epoxydodecane, styrene oxide, cyclohexene oxide orglycidyl alcohol. Propylene oxide is preferred. A particularly preferredmonoepoxide is epichlorohydrin. The monoepoxides (D) are in generalemployed in amounts of 1 to 80, preferably 1 to 40, and particularlypreferably 5 to 20 mol %, based on the content of basic amine functionsin the basic polyamidoamine which has been rendered hydrophobic.

However, the basic polyamidoamines which have been rendered hydrophobiccan also obtain their cationic charge by first being partly quaternisedin the manner mentioned, and then additionally being protonated byaddition of acid.

The cationic polyamidoamines which have been rendered hydrophobic andare employed as emulsifiers in the process according to the inventionare preferably obtained by condensation of polyamines a1) of the formula##STR6## wherein R₁, R₂ and R₃ independently of one another are H,methyl, ethyl or 2-hydroxyethyl,

a and b independently of one another represent 0, 1, 2, 3 or 4 and

c and d independently of one another represent 1, 2, 3, 4, 5 or 6,

and/or the formula ##STR7## wherein x represents 2 or 3 and

A represents hydrogen, aminoethyl or aminopropyl,

and if appropriate polyamines a2) of the formula ##STR8## wherein R₁,R₂, a and c have the abovementioned meaning,

with 80 to 120 mol % of dicarboxylic acids or derivatives thereof b) ofthe formula

    R.sub.4 --O--CO--(CH.sub.2).--CO--O--R.sub.5               (VI)

wherein

R₄ and R₅ independently of one another represent hydrogen, C₁ -C₆ -alkylor phenyl and

e represents 0 or an integer from 1 to 10,

based on the total molar amount of polyamines employed, subsequentrendering of the resulting basic polyamidoamines (A) hydrophobic with 10to 100 mol % of a longchain monocarboxylic acid (B) of the formula

    R.sub.6 --COOH                                             (VII)

wherein

R₆ represents straight-chain or branched, saturated or olefinicallyunsaturated alkyl having 7 to 31 C atoms,

and/or the formula

R₇ represents straight-chain or branched, saturated or olefinicallyunsaturated monohydroxyalkyl having 7 to 31 C atoms,

and/or the formula

    H--[--O--R.sub.6 --CO--].sub.f --OH                        (IX)

and/or the formula

    R.sub.6 --CO--]--O--R.sub.6 --CO--].sub.f --OH             (X)

or with 10 to 100 mol % of an acid chloride of the formula

    H--]--O--R.sub.6 --CO--].sub.f --Cl                        (XI)

and/or the formula

    R.sub.6 --CO--]--O--R.sub.6 --CO--].sub.f --Cl             (XII)

wherein, in each case,

R₆ and f have the abovementioned meanings,

and the mol % data for the formulae (VII) to (XII) in each case relateto the content of primary and secondary amine functions in the basicpolyamidoamine (A), subsequent protonation of the resultingpolyamidoamine, which has been rendered hydrophobic, with 50 to 100 mol% of dissociated protons of an acid (C), and/or quaternisation with 1 to80 mol % of a monoepoxide (D), in each case based on the content ofbasic amine functions in the polyamidoamine (A) which has been renderedhydrophobic.

In the process according to the invention, olefinically unsaturatedmonomers are subjected to free radical polymerisation in the presence ofthe emulsifiers described above in more detail.

Suitable monomers which can be polymerised by free radicals are, inparticular, styrene (derivatives), esters of (meth) acrylic acid, inparticular having C₁ -C₁₂ -alkyl radicals which are optionally furthersubstituted, and/or (meth)acrylonitrile, as well as mixtures of thesemonomers. Examples which may be mentioned are: styrene, α-methylstyrene,p-methylstyrene, p-ethylstyrene, p-chlorostyrene, acrylonitrile, vinylacetate, ethyl acrylate, methyl methacrylate, n-butyl acrylate, i-butylacrylate, 2-ethylhexyl acrylate and oxypropyl methacrylate.

Either the monomers by themselves or mixtures thereof with one anothercan be used for preparation of the vinyl polymer dispersions accordingto the invention. A monomer mixture of

d) 5 to 95, preferably 20 to 80% by weight of acrylonitrile,methacrylonitrile or styrene, or mixtures thereof,

and

e) 5 to 95, preferably 20 to 80% by weight of (meth)-acrylic acid esterhaving 1 to 12 C atoms in the alcohol radical

--the sum of components d) and e) always being 100% by weight-- isespecially preferably used for preparation of the vinyl polymerdispersions according to the invention.

(Meth)acrylic derivatives in the context of this invention arederivatives of methacrylic acid or of acrylic acid.

Suitable (meth)acrylic acid esters which are employed as comonomers inthe free radical copolymerisation are preferably those compounds whichform, with (meth) acrylonitrile or styrene or mixtures thereof,copolymers having film-forming temperatures below 100° C. Acrylates,such as methyl, ethyl, n-butyl and 2-ethylhexyl acrylate, andmethacrylates, such as methyl and n-butyl methacrylate, are suitable inprinciple. n-Butyl acrylate is particularly suitable. These(meth)acrylates can in each case be copolymerised by themselves or as amixture of various (meth)acrylates with methacrylonitrile, acrylonitrileor styrene, or with mixtures of two or three of the monomers mentionedlast. Acrylonitrile is the preferred copolymerisation partner. Thecontent of styrene, acrylonitrile or methacrylonitrile or of mixtures ofthese components can be between 5 and 95, preferably 20 and 80, andparticularly preferably between 40 and 60% by weight.

To prepare the vinyl polymer dispersions according to the invention, amonomer mixture of d) and e) is preferably emulsified in water in thepresence of 2 to 70% by weight, based on the monomer mixture, of acationic polyamidoamine which has been rendered hydrophobic, and theresulting emulsion is subjected, at temperatures of 20 to 150° C., toemulsion polymerisation initiated by free radicals.

In addition to the cationic polyamidoamine which has been renderedhydrophobic, a further cationic and/or nonionic auxiliary emulsifier canbe employed in amounts of 1 to 40% by weight, preferably 3 to 20% byweight, based on the above cationic polyamidoamine which has beenrendered hydrophobic, for preparation of the vinyl polymer dispersionsaccording to the invention. The nonionic emulsifier preferablycorresponds to the formula

    R.sub.6 --X--(CH.sub.2 --CHR.sub.9 --O).sub.n --(CH.sub.2 --CHR.sub.10 --O).sub.m --H                                            (XIII)

wherein

x represents oxygen, NH or COO,

R₆ represents a higher aliphatic, cycloaliphatic, araliphatic oraromatic hydrocarbon radical having 4 to 30 C atoms,

R_(g) and R₁₀ independently of one another represent alkyl radicalshaving 1 to 12 C atoms or hydrogen and

n and m independently of one another represent an integer between 2 and100.

The cationic auxiliary emulsifier preferably corresponds to the formula##STR9## wherein R₁₁ and R₁₂ independently of one another represent ahigher aliphatic or araliphatic hydrocarbon radical having 6 to 20 Catoms,

R₁₃ and R₁₄ independently of one another represent a lower aliphatichydrocarbon radical having 1 to 6 C atoms and

Y⁻ represents a halide ion.

Suitable nonionic auxiliary emulsifiers (XIII) are reaction products ofaliphatic, araliphatic, cycloaliphatic or aromatic carboxylic acids,alcohols, phenol derivatives or amines with epoxides, such as, forexample, ethylene oxide. Examples of these are reaction products ofethylene oxide with carboxylic acids, such as, for example, lauric acid,stearic acid, oleic acid, the carboxylic acids of castor oil or abieticacid, with longer-chain alcohols, such as oleyl alcohol, lauryl alcoholor stearyl alcohol, with phenol derivatives, such as, for example,substituted benzyl- or phenylphenols and nonylphenol, and withlonger-chain amines, such as, for example, dodecylamine andstearylamine. The reaction products with ethylene oxide are oligo- orpolyethers having degrees of polymerisation of between 2 and 100,preferably of 5 to 50.

Suitable cationic low molecular weight auxiliary emulsifiers arequaternary ammonium salts, such as, for example,benzyldodecyl-dimethyl-ammonium chloride.

Possible initiators for the emulsion polymerisation are, preferably,water-soluble nonionic peroxides which supply free radicals, such ashydrogen peroxide and tert-butyl hydroperoxide, as well as water-solubleazo compounds according to DE-A-2 841 045. Redox systems which compriseperoxidic initiators and reducing agents, such as amines, polyamines,thiourea, iron(II) salts and the like, are also suitable. Possibleinitiators are also water-insoluble initiators, such asazoisobutyronitrile and benzoyl peroxide. The latter are then dissolvedpractically only in the organic phase.

The initiators mentioned are added in amounts of 0.1 to 5% by weight,preferably 0.3 to 3% by weight, based on the monomer mixture.

Customary regulators, such as, for example, n-dodecylmercaptan,tert-dodecylmercaptan, diisopropylxanthogen disulphide, thioglycol andglycerol, can be employed for regulation of the molecular weights. Theyare added in amounts of 0. 1 to 2% by weight, based on the monomermixture.

The emulsion polymerisation in an aqueous medium can be carried out byknown polymerisation processes, either discontinuously or continuously,or in the feed process. The continuous process and the feed process areparticularly preferred. In the latter, water, together with some or allof the emulsifier system and if appropriate some of the monomer mixture,are initially introduced into the reaction vessel under a nitrogenatmosphere and are heated up to the polymerisation temperature of 20 to150° C., preferably 50 to 100° C., and the monomer mixture as well asthe initiator and if appropriate emulsifier are added dropwise in thecourse of 0.5 to 10 hours, preferably 1 to 6 hours.

After some time, the mixture is in general after-activated, and thereaction is brought to completion up to a conversion of about 98.0 to99.9%. After the emulsion copolymerisation, residue monomers are removedby distillation in vacuo. Water is then added in an amount such that anapproximately 10 to 35% strength by weight aqueous colloidally dispersesolution results. The viscosity of these dispersions, measured in arotary viscometer at 200° C., is in general below 50 mpas. The averageparticle diameters, measured by means of laser scattered lightspectroscopy, are between 15 and 300 nm, preferably between 50 and 150nm, depending on the reaction conditions.

The stability of the colloidally disperse vinyl polymers according tothe invention is also increased by grafted contents of the polymer onthe polymeric emulsifier employed in the form of the cationicpolyamidoamine which has been rendered hydrophobic. The polymer ofcomponents d) and e) and the cationic polyamidoamine which has beenrendered hydrophobic are thus to a large degree inseparable components,since they are chemically bonded, after the polymerisation.

The vinyl polymer dispersions according to the invention can be employedas sizing agents for paper and card by all the working methods customaryfor surface and beater sizing in papermaking. The cationicpolyamidoamines which have been rendered hydrophobic and are employedfor is preparation of the vinyl polymers can be prepared withoutaddition of solvents and therefore without pollution of the environmentand inexpensively.

The vinyl polymer dispersions according to the invention are preferablyemployed in amounts of 0.01 to 10% by weight of the solid contained inthe vinyl polymer dispersions, based on the weight of air-dried paper tobe produced.

When used as surface sizing agents, the vinyl polymers according to theinvention can also be employed on paper which has been subjected tobeater presizing. In addition to the vinyl polymer dispersions accordingto the invention themselves, it is of course also possible to usecommercially available cationic beater sizing agents for this presizing.

Furthermore, it may be advantageous to add to the vinyl polymerdispersions according to the invention commercially available cationicretention agents as sizing intensifiers for paper sizing. These cationicpolymers are known per se and are derived, in particular, frompolyamidoamines (EP 2 474, DE-A-1 802 435), diallyldimethylammoniumchlorides (EP 262 945) or modified polyacrylamides (US 3 323 979). Ingeneral, 0.02 to 1% by weight, preferably 0.1 to 0.5% by weight, of aretention agent is added.

PREPARATION EXAMPLES 1. Precursors Example 1.1 Polyamidoamine P 1

2,178 g of bis(3-aminopropyl)methylamine and 2,103 g of adipic acid wereintroduced into the reaction vessel together at 1500° C., while passingnitrogen over, and were heated slowly to 1900° C., the water of reactionbeing distilled off. After 8 hours, the mixture was cooled. Theresulting brittle, brownish solid had a residual content of primaryamino groups of 0.26% ("van Slyke" determination at room temperature).

Example 1.2 Polyamidoamine P 2

1,450 g of bis(3-aminopropyl)methylamine and 1,314 g of adipic acid weresubjected to condensation at temperatures between 150 and 210° C. for 10hours, using a water separator, as described for polyamidoamine P 1. Theresidual content of primary amine in the resulting product was 0.36%.

Example 1.3 Hydroxycarboxylic Acid Polycondensate H 1

2,019 g of 12-hydroxystearic acid, 224 g of stearic acid, 108 g ofpalmitic acid, 8 g of myristic acid and 3 g of p-toluenesulphonic acidwere introduced into 1 l of m-xylene, and the mixture was boiled, usinga water separator, until the resulting clear, brownish oil had aresidual acid number of 57.8.

Example 1.4 Hydroxycarboxylic Acid Polycondensate H 2

4,382 g of 12-hydroxystearic acid, 35 g of stearic acid and 5.9 g ofp-toluenesulphonic acid were introduced into 2 l of m-xylene, and themixture was boiled, using a water separator, until the resulting clear,brownish oil had a residual acid number of 23.8 and an OH number of 13.

Example 1.5 Hydroxycarboxylic Acid Polycondensate H 3

1,873 g of 12-hydroxystearic acid, 290 g of stearic acid, 35 g ofpalmitic acid, 3 g of myristic acid and 1.5 g of tetrabutylorthotitanate were introduced into 550 g of xylene, and the mixture washeated for 24 hours, using a water separator. A clear, brownish oilhaving an acid number of 43 was formed.

Example 1.6 Acylated Hydroxycarboxylic Acid Polycondensate AcH2

161 g of stearic acid, 77 g of palmitic acid and 6 g of myristic acidwere added to 3,700 g of hydroxycarboxylic acid polycondensate H 2, andthe mixture was heated first at 140° C. for 6 hours and then at 170° C.for 2 hours. Excesses of the carboxylic acids employed could be filteredvia a filter of 50 mm pore width, after cooling. The resulting oilyproduct had a residual OH number of 4.5 and an acid number of 23.4.

Example 1.7 Activated Hydroxycarboxylic Acid Polycondensate ActH1

250 g of thionyl chloride were briskly added dropwise to 1,000 g ofhydroxycarboxylic acid polycondensate H 1 at room temperature, whilepassing nitrogen over, and the mixture was then subsequently stirred at90° C. for 6 hours. After volatile constituents had been stripped off at80° C. under 0.1 mbar, a dark brown oil was obtained, in which,according to quantitative IR analysis, all the acid groups had beenreacted to give acid chloride functions.

IR (film): υ2920, 2850, 1808, 1733, 1465, 1380, 1255, 180, 1115, 970,733 cm⁻¹.

Example 1.8 Activated Hydroxycarboxylic Acid Polycondensate ActH2

1,000 g of acylated hydroxycarboxylic acid polycondensate AcH2 werereacted with 250 g of thionyl chloride as described for ActH1. In theresulting dark brown oil, according to IR analysis, all the acid groupshad been converted into acid chloride functions.

IR (film): υ2920, 2860, 1810, 1740, 1650, 1550, 1485, 382, 1260, 1180,1120, 735 cm⁻¹

2. Preparation of the Polymeric Emulsifier Example 2.1 PolyamidoamineRendered Hydrophobic HP 1

185 g of activated hydroxycarboxylic acid polycondensate ActH1 wereadded dropwise to 1,356 g of polyamidoamine P 1 at 165° C. in the courseof 0.5 hour, while passing nitrogen over and stirring. The mixture wassubsequently stirred for 5 hours, and a beige solid was obtained which,according to IR analysis, was free from acid chloride functions.

IR (film): υ=3270, 3060, 2940, 2873, 2800, 2320, 1740, 640, 1550, 1463,1380, 1250, 1200, 1160, 1060 cm⁻¹

Example 2.2 Polyamidoamine Rendered Hydrophobic HP 2

1,449 g of polyamidoamine P 1 were reacted with 325 g of activatedhydroxycarboxylic acid polycondensate ActH2 as described for HP 2.According to IR analysis, the resulting beige solid was free from acidchloride functions.

IR (film): υ3270, 3050, 2930, 2800, 2320, 1640, 1550, 1460, 1380, 1275,1150, 1090, 1058 cm⁻¹

Example 2.3 Polyamidoamine Rendered Hydrophobic HP 3

2,178 g of bis(3-aminopropyl)methylamine and 2,103 g of adipic acid wereheated for 8 hours, using a water separator, starting at 150° C. andwith the temperature rising to 200° C. The content of primary amineafter this time was 0.3% (measured by the "van Slyke" method at roomtemperature). A mixture of 135 g of stearic acid, 65 g of palmitic acidand 5 g of myristic acid was then added briskly, and the condensationwas continued at 200° C. for 2.5 hours, using a water separator. Aftercooling, a dark brown solid was obtained.

IR (film): υ3250, 2920, 1650, 1552, 1450, 1380, 1260, 1155, 1040 cm⁻¹

Example 2.4 Polyamidoamine Rendered Hydrophobic HP 4

1,938 g of N-2-aminoethylpiperazine and 2,103 g of adipic acid wereheated for 8 hours, using a water separator, first at 180° C. and, asthe reaction progressed, at 200° C. A mixture of 258 g of docosenoicacid, 14 g of eicosenoic acid and 5 g of octadecenoic acid was thenadded, and the mixture was heated for a further 8 hours, using a waterseparator. After cooling, a yellowish solid was obtained.

IR (film): υ3300, 2920, 1620, 1550, 1440, 1240, 1155, 1030, 1008 cm⁻¹

Example 2.5 Cationic Polyamidoamine Rendered Hydrophobic CHP 1

200 g of product HP 1 were stirred into a mixture of 1,760 g of waterand 40 g of glacial acetic acid, so that no residue remained onfiltration over a 50 μm filter. The resulting solution was then stirredat 9500 revolutions/minute for 5 minutes.

Example 2.6 Cationic Polyamidoamine Rendered Hydrophobic CHP 2

A solution was prepared from 200 g of product HP 2, 1,760 g of water and40 g of glacial acetic acid as described for CHP 1.

Example 2.7 Cationic Polyamidoamine Rendered Hydrophobic CHP 3

200 g of product HP 3 were dissolved in a mixture of 1,800 g of waterand 45 g of glacial acetic acid at room temperature.

Example 2.8 Cationic Polyamidoamine Rendered Hydrophobic CHP 4

444 g of polyamidoamine P 2 and 261 g of hydroxycarboxylic acidpolycondensate H 3 were introduced into the reaction vessel together,and were heated, using a water separator, first at 150° C. for 2 hoursand then at temperatures rising to 200° C. for 4 hours. After cooling to90° C., 1,600 g of water and 125 g of glacial acetic acid were added tothe resulting condensate and the mixture was filtered over a 200 mmfilter (solids content 28.7%).

Example 2.9 Cationic Polyamidoamine Rendered Hydrophobic CHP 5

200 g of product HP 4 were dissolved in a mixture of 2,300 g of waterand 488 g of glacial acetic acid at room temperature.

3. Preparation of the Emulsion Polymers Example 3.1 Emulsion Polymer E 1

    ______________________________________                                        Solution 1:                                                                              1,030 g of cationic polyamidoamine                                            rendered hydrophobic CHP 1                                                    1,030 g of water                                                   Solution 2:                                                                              291.5 g of acrylonitrile                                                      291.5 g of n-butyl acrylate                                        Solution 3:                                                                              1.6 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                  Solution 4:                                                                              16.3 g of 30% strength by weight aqueous                                      hydrogen peroxide                                                             686 g of water                                                     Solution 5:                                                                              3.9 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                             39 g of water                                                      ______________________________________                                    

Solution 3 and 2.00 ml of solution 2 were briskly added to solution 1 at70° C., while stirring, in an apparatus which was flushed thoroughlywith nitrogen. After 0.5 hour, solution 4 and the remainder of solution2 were metered in synchronously over 2 hours, and the mixture wassubsequently stirred for 3 hours. After brisk addition of solution 5,the mixture was subsequently stirred for a further 3 hours. The batchwas then degassed by distilling off 400 ml of liquid under 150 mbar, andwas cooled and filtered over a 100 #m filter. 400 ml of water were addedto the filtrate.

The resulting colloidally disperse solution had a solids content of15.4% by weight and an average particle diameter of 165 nm.

Example 3.2 Emulsion Polymer E 2

    ______________________________________                                        Solution 1:                                                                              950 g of cationic polyamidoamine rendered                                     hydrophobic CHP 2                                                             950 g of water                                                     Solution 2:                                                                              269.0 g of acrylonitrile                                                      269.0 g of n-butyl acrylate                                        Solution 3:                                                                              1.5 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                  Solution 4:                                                                              15.0 g of 30% strength by weight aqueous                                      hydrogen peroxide                                                             63.3 g of water                                                    Solution 5:                                                                              3.6 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                             36 g of water                                                      ______________________________________                                    

The emulsion polymerisation was carried out as described for polymer E1.

The resulting colloidally disperse solution had a solids content of14.9% by weight and an average particle diameter of 171 nm.

Example 3.3 Emulsion Polymer E 3

    ______________________________________                                        Solution 1:                                                                              745 g of cationic polyamidoamine rendered                                     hydrophobic CHP 3                                                             1,195 g of water                                                   Solution 2:                                                                              274.0 g of acrylonitrile                                                      274.0 g of n-butyl acrylate                                        Solution 3:                                                                              1.5 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                  Solution 4:                                                                              15.2 g of 30% strength by weight aqueous                                      hydrogen peroxide                                                             63.5 g of water                                                    Solution 5:                                                                              3.7 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                             36.7 g of water                                                    ______________________________________                                    

The emulsion polymerisation was carried out as described for polymer E1.

The resulting colloidally disperse solution had a solids content of18.1% by weight and an average particle diameter of 107 nm.

Example 3.4 Emulsion Polymer E 4

    ______________________________________                                        Solution 1:                                                                              523 g of cationic polyamidoamine rendered                                     hydrophobic CHP 4                                                             2,450 g of water                                                   Solution 2:                                                                              425.0 g of acrylonitrile                                                      425.0 g of n-butyl acrylate                                        Solution 3:                                                                              2.0 g of 35% strength by weight aqueous                                       hydrogen peroxide                                                  Solution 4:                                                                              20.0 g of 35% strength by weight aqueous                                      hydrogen peroxide                                                             1,000 g of water                                                   Solution 5:                                                                              5.0 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                             50.0 g of water                                                    ______________________________________                                    

The emulsion polymerisation was essentially carried out as described forpolymer E 1. Finally, 500 ml of liquid were distilled off, for degassingof volatile constituents, and were not replaced by water.

The resulting colloidally disperse solution had a solids content of20.5% by weight and an average particle diameter of 160 nm.

Example 3.5 Emulsion Polymer E 5

    ______________________________________                                        Solution 1:                                                                              960 g of cationic polyamidoamine rendered                                     hydrophobic CHP 5                                                             1,040 g of water                                                   Solution 2:                                                                              288.0 g of acrylonitrile                                                      288.0 g of n-butyl acrylate                                        Solution 3:                                                                              1.7 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                  Solution 4:                                                                              16.0 g of 30% stren9th by weight aqueous                                      hydrogen peroxide                                                             65.0 g of water                                                    Solution 5:                                                                              3.9 g of 30% strength by weight aqueous                                       hydrogen peroxide                                                             36.4 g of water                                                    ______________________________________                                    

The emulsion polymerisation was carried out as described for polymer E1.

The resulting colloidally disperse solution had a solids content of20.2% by weight and an average particle diameter of 120 nm.

4. Comparison Example

A sizing agent according to Example 12 DE-A-3 537 824, the cationicemulsifier on which it is based having been prepared in isopropanol,which was distilled off after the emulsion polymerisation had takenplace, is used as the comparison in the use examples.

5. Use Examples

The following use examples show the good usability of the novel vinylpolymer dispersions as sizing agents in papermaking.

The good usability as sizing agents is described for papers of variouscompositions, under various sizing conditions and according to variousevaluation methods:

Paper types

    ______________________________________                                        Alum-free paper:                                                                            50% by weight of bleached softwood                                            pulp,                                                                         50% by weight of bleached hardwood                                            pulp,                                                                         9.5% of clay ash,                                                             degree of beating 35° C. SR,                                           pH: 7.0 to 7.5,                                                               weight per unit area: about 80 g/m.sup.2                        Chalk-containing                                                                            50% by weight of bleached softwood                              paper:        pulp,                                                                         40% by weight of bleached hardwood                                            pulp,                                                                         7.9% of chalk ash,                                                            degree of beating 35° C. SR,                                           pH: 7.2 to 7.5,                                                               weight per unit area: about 80 g/m.sup.2                        ______________________________________                                    

Sizing conditions

    ______________________________________                                        Beater sizing:                                                                            The stated amount of vinyl polymer                                            dispersion is added to a 0.5% strength                                        by weight aqueous pulp mixture of 50                                          parts of bleached softwood pulp, 50                                           parts of bleached hardwood pulp, 20                                           parts of chalk and 0.2 part of reten-                                         tion agent Retaminol ® H, while stirring.                                 After a short action time (10 to 20                                           seconds), a sheet of paper is formed                                          on a laboratory sheet former. This is                                         pressed off between felts and then                                            dried at 100° C. in a drying cylinder.                     Surface sizing:                                                                           Sizing of the above papers was carried                                        out on a laboratory sizing press from                                         Mathis, Zurich/Switzerland model HF. A                                        solution of 5% strength by weight of                                          commercially available potato starch                                          (Perfectamyl ® A 4692) and the stated                                     amount (see table) of the vinyl polymer                                       dispersion to be tested in water was                                          used as the sizing liquor. These papers                                       are dried in a drying cylinder at                                             100° C.                                                    ______________________________________                                    

Evaluation method

    ______________________________________                                        Cobb test: According to DIN 53132, the absorption                                        of water on one side of the paper over                                        a test period of 60 seconds is used to                                        evaluate the sizing action.                                        Ink flotation                                                                            Test papers having dimensions of 7 × 3 cm                    test (IFT):                                                                              are placed on blue test ink (DIN 53126)                                       at 22° C. After test periods, which vary                               for the individual types of paper, the                                        samples of paper are removed from the                                         ink, the reverse is pressed off on                                            blotting paper and, after drying, the                                         penetration of the ink to the surface                                         is evaluated visually as a measure of                                         the sizing action. No penetration is                                          rated with 1, complete penetration with                                       5. The intermediate values lie pro-                                           portionally in between.                                            ______________________________________                                    

The tendency to foam, which is critical for many sizing agents duringuse, was moreover evaluated as follows.

0.4% by weight of the active substance of the vinyl polymer dispersionis introduced into a sizing liquor of 5% strength by weight ofcommercially available potato starch (Perfectamyl® A 4692), and themixture is heated to 60° C. 200 ml of this sizing liquor are poured outof an aluminium vessel, which has a circular opening of 4 mm diameter(Ford cup) on its underside, from a height of 60 cm, falling freely intoa graduated flask beaker. The volume (in ml) of foam which forms abovethe surface of the liquid is determined on the one hand immediately, andafter standing in air for one minute. The first value providesinformation on the tendency of the sizing agent to foam, and the secondvalue on the speed of breakdown of the foam or the stability thereof.

                  TABLE 1                                                         ______________________________________                                        Tendency of sizing agents to foam                                                        Foam volume in ml                                                  Sizing agent                                                                             immediate     after time t                                         ______________________________________                                        E1         60            0 (t = 30 seconds)                                   E2         40            0 (t = 23 seconds)                                   E3         80            0 (t = 45 seconds)                                   E4          0            0                                                    E5         40            0 (t = 25 seconds)                                   Comparison 90            50 (t = 60 seconds)                                  ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                        Surface sizing on alum-free paper                                                    Cobb values in g/ml with addition of                                          0.8% by weight                                                                          1.0% by weight                                                                            2.0% by weight                                   Sizing agent                                                                           of sizing agent (based on the pure active substance)                 ______________________________________                                        E1       50          33                                                       E2       43          32                                                       E5                               21.9                                         Comparison                                                                             56          38          22.1                                         ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Surface sizing on alum-free paper                                             Sizing agent                                                                  ______________________________________                                                      1st measurement pass                                                          IFT evaluation after a test time of                                           5 minutes and addition                                                        of 1% by weight                                                               of sizing agent (based on the pure                                            active substance)                                               E1            2                                                               E2            2                                                               Comparison    2                                                                             2nd measurement pass                                                          IFT evaluation after a test time of                                           1 minute and addition                                                         of 0.2% by weight                                                             of sizing agent (based on the pure                                            active substance)                                               E2            1.5                                                             E3            1.5                                                             Comparison    1.5                                                                           3rd measurement pass                                                          IFT evaluation after a test time of                                           5 minutes and addition                                                        of 1% by weight                                                               of sizing agent (based on the pure                                            active substance)                                               E             1.5                                                             Comparison    1                                                                             4th measurement pass                                                          IFT evaluation after a test time of                                           3 minutes and addition                                                        of 2% by weight                                                               of sizing agent (based on the pure                                            active substance)                                               E5            1                                                               Comparison    1                                                               ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Surface sizing on chalk-containing paper                                      Sizing agent                                                                  ______________________________________                                                      1st measurement pass                                                          IFT evaluation after a test time of                                           5 minutes and addition                                                        of 1% by weight                                                               of sizing agent (based on the pure                                            active substance)                                               E1            1.5                                                             E2            1.5                                                             Comparison    1.5                                                                           2nd measurement pass                                                          IFT evaluation after a test time of                                           10 minutes and addition                                                       of 1% by weight                                                               of sizing agent (based on the pure                                            active substance)                                               E4            1.5                                                             Comparison    1.5                                                             ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Beater sizing of chalk-containing paper                                                  Cobb values in g/ml with addition                                             of 0.6% by weight of sizing agent                                  Sizing agent                                                                             (based on the pure active substance)                               ______________________________________                                        E1         27                                                                 E2         26                                                                 E3         24                                                                 E5         22                                                                 Comparison 21                                                                 ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                        Beater sizing of chalk-containing paper                                                  IFT evaluation after a test period                                            of 25 minutes and addition                                                    of 0.6% by weight of sizing agent                                  Sizing agent                                                                             (based on the pure active substance)                               ______________________________________                                        E1         2                                                                  E2         1.5                                                                E3         1.5                                                                E5         1.5                                                                Comparison 1.5                                                                ______________________________________                                    

The above results during use show that the vinyl polymer dispersionsaccording to the invention have clearly improved foam properties with acomparably good sizing action in comparison with the sizing agentaccording to Example 12 of DE-A-3 537 824. Furthermore, the sizingagents according to the invention are prepared in melts or water,without using organic solvents, and are therefore distinguished byecological advantages over the prior art.

What is claimed is:
 1. A process for sizing paper which comprisescontacting the paper with a vinyl polymer dispersion obtained byemulsion polymerization, initiated by free radicals, of olefinicallyunsaturated monomers in an aqueous medium, the olefinically unsaturatedmonomers comprisinga) 5 to 95% by weight of acrylonitrile,methacrylonitrile, styrene or mixtures thereof and b) 5 to 95% by weightof a (meth)acrylic acid ester having 1 to 12 C atoms in the alcoholradical, the sum of components a) and b) totalling 100% by weight,andthe emulsifier in said emulsion polymerization comprising a cationicpolyamidoamine which has been rendered hydrophobic, has a content ofcationic groups of between 0.01 and 0.3 charge equivalent per 100 g, acontent of hydrophobic groups of between 0.5 and 50% by weight and acontent of basic nitrogen atoms of between 0 and 3% by weight, in eachcase based on the cationic polyamidoamine which has been renderedhydrophobic, the polyamidoamine having been obtained by reaction of abasic polyamidoamine (A) with a monocarboxylic acid (B) and at least oneof subsequent protonation with an acid (C) and quaternization with amonoepoxide (D).
 2. The process of claim 1, in which the cationicpolyamidoamine which has been rendered hydrophobic is obtained byreaction of a basic polyamidoamine (A) with a monocarboxylic acid (B)and subsequent quaternization with a monoepoxide (D).
 3. The process ofclaim 1, in which the cationic polyamidoamine which has been renderedhydrophobic is obtained by reaction of a basic polyamidoamine (A) with amonocarboxylic acid (B) and subsequent protonation with an acid (C). 4.The process according to claim 1, in which the basic polyamidoamine (A)employed is a condensation product comprising structural units which arederived froma1) a polyamine which contains at least two amino groupswhich are capable of amide formation and at least one other secondary ortertiary amino group,and b) at least one of a saturated aliphaticdicarboxylic acid, an unsaturated aliphatic dicarboxylic acid, anaromatic dicarboxylic acid and a functional derivative thereof.
 5. Theprocess according to claim 4, in which 0.8 to 1.2 mol of component a1)is employed per mol of component b).
 6. The process according to claim1, in which the basic polyamidoamine (A) is a condensation productcomprising structural units which are derived froma1) a polyamine whichcontains at least two amino groups which are capable of amide formationand at least one other secondary or tertiary amino group,and b) at leastone of an aliphatic dicarboxylic acid, an unsaturated aliphaticdicarboxylic acid, an aromatic dicarboxylic acid and a functionalderivative thereof,and at least one of a2) a polyamine which containstwo amino groups which are capable of amide formationand c) anomega-aminocarboxylic acid or a lactam.
 7. The process of claim 6, inwhich the structural units are derived from 0.8 to 1.2 mol of componenta1), up to 0.8 mol of component a2), and up to 1.5 mol of component c)per mol of component b), the molar ratio of a1)+a2):b) ranging between0.8:1 to 1.2:1.
 8. The process according to claim 1, in which themonocarboxylic acid (B) is selected from the group consisting ofcompounds of the formula

    R.sub.6 --COOH                                             (VII)

wherein R₆ represents straight-chain or branched, saturated orolefinically unsaturated alkyl having 7 to 31 C atoms, compounds of theformula

    R.sub.7 --COOH                                             (VIII)

wherein R₇ represents straight-chain or branched, saturated orolefinically unsaturated monohydroxyalkyl having 7 to 31 C atoms,compounds of the formula

    H--[--O--R.sub.6 --CO--].sub.f --OH                        (IX)

wherein f represents an integer from 2 to 50,and compounds of theformula

    R.sub.6 --CO--[--O--R.sub.6 --CO--].sub.f --OH             (X).


9. The process according to claim 1, in which there is employed as themonocarboxylic acid B) at least one functional derivative which isselected from the group consisting of compounds of the formula

    H--[--O--R.sub.6 --CO--].sub.f --Cl                        (XI)

and

    R.sub.6 --CO--[--O--R.sub.6 --CO--].sub.f --Cl             (XII)

wherein R₆ represents straight-chain or branched, saturated orolefinically unsaturated alkyl having 7 to 31 C atoms,and f representsan integer from 2 to
 50. 10. The process according to claim 1, in whichthe acid (C) employed is an inorganic acid or an organic carboxylic acidhaving a lower alkyl chain which contains 1 to 4 C atoms.
 11. Theprocess according to claim 1, in which the monoepoxide (D) employed isethylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, isobutyleneoxide, 1,2-epoxydecane, 1,2-epoxydodecane, styrene oxide, cyclohexaneoxide, glycidyl alcohol, propylene oxide or epichlorohydrin.
 12. Theprocess according to claim 1, in which the emulsifier employed is acationic polyamidoamine which has been rendered hydrophobic and isobtained by condensation of at least one polyamine a1) of the formula##STR10## wherein R₁, R₂ and R₃ independently of one another are H,methyl, ethyl or 2-hydroxyethyl,a and b independently of one anotherrepresent 0, 1, 2, 3 or 4 and c and d independently of one anotherrepresent 1, 2, 3, 4, 5 or 6,or the formula ##STR11## wherein xrepresents 2 or 3 and A represents hydrogen, aminoethyl oraminopropyl,and optionally polyamines a2) of the formula ##STR12## with80 to 120 mol % of a dicarboxylic acid or derivative b) thereof of theformula

    R.sub.4 --O--CO--(CH.sub.2).sub.e --CO--O--R.sub.5

wherein R₄ and R₅ independently of one another represent hydrogen, C₁-C₆ -alkyl or phenyl, and e represents 0 or an integer from 1 to10,based on the total molar amount of polyamines employed, subsequentreaction of the resulting basic polyamidoamines (A) with 10 to 100 mol %of at least one long-chain monocarboxylic acid (B) of the formula

    R.sub.6 --COOH                                             (VIII)

wherein R₆ represents straight-chain or branched, saturated orolefinically unsaturated alkyl having 7 to 31 C atoms,of the formula

    R.sub.7 --COOH                                             (VIII)

wherein R₇ represents straight-chain or branched, saturated orolefinically unsaturated monohydroxyalkyl having 7 to 31 C atoms,of theformula

    H--[--O--R.sub.6 --CO--].sub.f --OH                        (IX)

or the formula

    R.sub.6 --CO--[--O--R.sub.6 --CO--].sub.f --OH             (X)

or with 10 to 100 mol % of at least one acid chloride of the formula

    H--[--O--R.sub.6 --CO--].sub.f --Cl                        (XI)

or the formula

    R.sub.6 --CO--[--O--R.sub.6 --CO--].sub.f --Cl             (XII)

wherein f represents an integer from 2 to 50, the mole % data for theformulae (VII) to (XII) in each case relating to the content of primaryand secondary amine functions in the basic polyamidoamine (A),subsequent protonation of the resulting polyamidoamine, which has beenrendered hydrophobic, with at least one of 50 to 100 mol % ofdissociated protons of an acid (C) and quaternization with 1 to 80 mol %of a monoepoxide (D), in each case based on the content of basic aminefunctions in the polyamidoamine (A) which has been rendered hydrophobic.13. The process according to claim 1, in which a monomer mixture of a)and b) is emulsified in water in the presence of 2 to 70% by weight of acationic polyamidoamine which has been rendered hydrophobic, thepercentages by weight being based on the monomer mixture employed, theresulting emulsion being subjected, at a temperature of 20° to 150° C.,to an emulsion polymerization initiated by free radicals.